SAN MATEO — One person was killed and another critically injured Sunday morning after a broken down pickup truck caused a multiple car pile up on southbound U.S. Highway 101 near the East Poplar Avenue exit, the California Highway Patrol reported.

The accident, which occurred at about 12:52 a.m., resulted in the closure of all but one lane on the freeway for about 2 ½ hours, the CHP said. The scene was cleared and the lanes reopened at about 4 a.m.

At least four cars were involved in the crash which is still under investigation, the CHP said.

Violent police encounters in California last year led to the deaths of 157 people and six officers, the state attorney general’s office said Thursday in a report that provides the first statewide tally on police use-of-force incidents.